Java Based Controller Interface

/**
 * The values provided by this interface are passed to the controller during
 * initialization and does not change during the simulation
 */
public interface Parameters {

    /**
     * @return the name of the wind turbine which this controller is attached to
     */
    String getTurbineName();

    /**
     * @return the sample time this controller will be stepped with
     */
    double getSampleTime();

    /**
     * @return the configuration string associated with this controller. Often,
     *         this will be the filepath to a configuration file.
     */
    String getConfigurationString();

    /**
     * @return the number of turbine blades on the turbine controlled by this
     *         controller
     */
    int getNumBlades();
}

/**
 * Measurements of turbine properties.
 *
 * For a RIFLEX wind turbine the shaft measurement system is used for the hub
 * position, velocity and acceleration measurements and may be chosen for the
 * additional nodal measurements. This coordinate system is determined from the
 * stress-free orientation of the shaft element where the electrical torque is
 * applied:
 *    - the local z-axis is vertical,
 *    - the local x-is the horizontal projection of the element’s x axis
 *    - the local y-axis is oriented so that the x-, y- and z-axes are a
 *      right-handed coordinate system (i.e. the y-axis is the vector cross
 *      product of the local z- and x-aces)
 *
 * If the stress-free orientation of the shaft is in the global X-Z plane, the
 * shaft measurement coordinate system will coincide with the global coordinate
 * system.
 *
 * NOTE: For a RIFLEX wind turbine it is not recommended to use the exported
 * accelerations directly in an external wind turbine controller. Instead, the
 * external controller should itself derive an improved estimate of the
 * accelerations based on the displacement values from several time steps. The
 * inaccuracies are a result of the Newton-Raphson iteration methods used in
 * the time domain simulation.
 */
public interface Measurements {

	/**
	 * @return current rotational speed of rotor [rad/T]
	 */
	public double getOmega();

	/**
	 * @return blade pitch angle in radians for blade number i [rad]
	 * @param i blade number to get pitch angle for, starting at 0
	 */
	public double getPitchAngle(int i);

	/**
	 * @return blade root bending moment about local x-axis for blade number
	 *         i [F*L]
	 * @param i blade number to get pitch angle for, starting at 0
	 */
	public double getBladeRootBMX(int i);

	/**
	 * @return blade root bending moment about local y-axis for blade number
	 *         i [F*L]
	 * @param i blade number to get pitch angle for, starting at 0
	 */
	public double getBladeRootBMY(int i);

	/**
	 * @return blade root bending moment about local z-axis for blade number
	 *         i [F*L]
	 * @param i blade number to get pitch angle for, starting at 0
	 */
	public double getBladeRootBMZ(int i);


	/**
	 * @return blade root aerodynamic torque for blade number i [F*L]
	 * @param i blade number to get pitch angle for, starting at 0
	 */
	public double getBladeRootAeroTor(int i);

	/**
	 * For a RIFLEX wind turbine:
	 * Returns dynamic displacement and rotation from final static
	 * position / orientation for the node at the second end of the shaft
	 * flex-joint. Values are in the shaft measurement system is used.
	 *
	 * For a SIMO wind turbine:
	 * Returns the global position of the hub body.
	 *
	 * @return turbine position including translations [L] and rotations [rad]
	 */
	public double[] getPosition();

	/**
	 * For a RIFLEX wind turbine:
	 * Returns velocity for the node at the second end of the shaft flex-joint.
	 * Values are in the shaft measurement system.
	 *
	 * For a SIMO wind turbine:
	 * Returns the hub velocity in the body-local coordinate system
	 *
	 * @return turbine velocity including translations [L/T] and
	 *         rotations [rad/T]
	 */
	public double[] getVelocity();


	/**
	 * For a RIFLEX wind turbine:
	 * Returns accelerations for the node at the second end of the shaft
	 * flex-joint. Values are in the shaft measurement system. Please see the
	 * warning above regarding the low accuracy of the exported accelerations.
	 *
	 * For a SIMO wind turbine:
	 * Currently not used.
	 *
	 * @return turbine accelerations including translations [L/T^2] and
	 *         rotations [rad/T^2]
	 */
	public double[] getAcceleration();

	/**
	 * @return three component hub wind velocity given in the global coordinate
	 *         system
	 */
	public double[] getHubWindVelocity();

	/**
	 * @return number of nodes with additional measurements
	 */
	public int getNnodMeas();

	/**
	 * For a RIFLEX wind turbine:
	 * Returns nodal measurements for measurement i. 18 values for each node:
	 *     - 3 displacements [L].
	 *     - 3 rotations relative to the stress-free configuration [rad].
	 *     - 6 velocities [L/T] or [rad/T].
	 * 	   - 6 accelerations [L/T^2] or [rad/T^2]. The rotations (R1,R2,R3) are
	 *         taken in the order R3, R2, R1 ; i.e. first rotation around the
	 *         global z-axis, then around the local (rotated) y-axis and then
	 *         finally around the local (rotated) x-axis. Global or shaft
	 *         measurement system as selected by input.
	 * Please see the warning above regarding the low accuracy of the exported
	 * accelerations.
	 *
	 * For a SIMO wind turbine:
	 * Currently not used.
	 *
	 * @return additional measurements for node measurement i
	 *         (0, 1, ... nnodMeas-1)
	 */
	public double[] getAddNodeMeas (int i);

    /**
	 * @return number of elements with additional measurements
	 */
	public int getNelMeas();

	/**
	 * For a RIFLEX wind turbine:
	 * Returns element measurements for the specified measurement i. 10 values
	 * for each element, all given in the local element system:
	 *     - Effective tension [F]
	 *     - Torsional moment [FL]
	 *     - My-moment end 1 and 2 [FL]
	 *     - Mz-moment end 1 and 2 [FL]
	 *     - Qy-shear force end 1 and 2 [F]
	 *     - Qz-shear force end 1 and 2 [F]
	 *
	 * For a SIMO wind turbine:
	 * Currently not used.
	 * @return additional measurements for element measurement i
	 *         (0, 1, ... nelMeas-1)
	 */
	public double[] getAddNelMeas (int i);

	/**
	 * @return the current yaw misalignment. Angle between shaft direction and
	 *         wind direction in shaft system local xy-plane. Seen from above,
	 *         the positive direction is counter-clockwise. [rad]
	 */
	public double getYawErr();

	/**
	 * @return the Azimuth angle.The angular position of blade 1 [rad],
         * where 0 is with blade 1 pointing upwards.
	 */
	public double getAzimuthAngle();
}

/**
 * This interface is used by the control system to return values to the
 * simulation. For each method setting a value there's a corresponding
 * get-method which will return the current value.
 */
public interface Feedback {

	/**
	 * Set the torque reference
	 * @param value torque reference
	 */
	public void setTorqueReference(double value);

	/**
	 * @return the current torque reference
	 */
	public double getTorqueReference();

	/**
	 * Set pitch angle reference for blade i
	 * @param i blade number, starting at 0 for the first blade
	 * @param value pitch angle reference
	 */
	public void setPitchAngleReference(int i, double value);

	/**
	 * @return the current pitch angle reference for blade i
	 * @param i blade number, starting at 0 for the first blade
	 */
	public double getPitchAngleReference(int i);

	/**
	 * Set gear shaft rotational speed for result presentation
	 * @param value gear shaft rotational speed
	 */
	public void setGearShaftOmega(double value);

	/**
	 * @return the current gear shaft rotational speed
	 */
	public double getGearShaftOmega();

	/**
	 * Set generated power for result presentation
	 * @param value generated power
	 */
	public void setGeneratedPower(double value);

	/**
	 * @return the current generated power
	 */
	public double getGeneratedPower();

	/**
	 * Set the current yaw control feedback [rad/s]
	 * @param value current yaw control feedback
	 */
	public void setYawCntrl(double value);

	/**
	 * @return the current yaw control feedback [rad/s]
	 */
	public double getYawCntrl();
}

throw new RuntimeException("Provide a message explaining what went wrong here");

package my.external.controller;

import no.marintek.wind.control.Feedback;
import no.marintek.wind.control.IController;
import no.marintek.wind.control.Measurements;

public class ExternalWindTurbineController implements IController {

	@Override
	public void init(double dt, int nblades, String config) {
		// ...
	}

	@Override
	public void step(Measurements measurements, Feedback feedback) {
		// ...
	}

	@Override
	public void finish() {
		// ...
	}
}

package my.external.controller;

import no.sintef.ocean.control.wind.Feedback; (1)
import no.sintef.ocean.control.wind.Measurements;
import no.sintef.ocean.control.wind.Parameters; (2)
import no.sintef.ocean.control.wind.WindTurbineController; (3)

public class ExternalWindTurbineController implements WindTurbineController { (4)

	@Override
	public void init(Parameters parameters) { (5)
		double dt = parameters.getSampleTime(); (6)
		int nblades = parameters.getNumBlades();
		String config = parameters.getConfigurationString();
		// ...
	}

	@Override
	public void step(Measurements measurements, Feedback feedback) {
		// ...
	}

	@Override
	public void finish() {
		// ...
	}
}